A composite function accelerometer

Abstract

The application discloses a composite function accelerometer in the field of micro-electro-mechanical system technology, and aims to solve the problem of poor integration and miniaturization in the prior art. The accelerometer comprises: when a MEMS generates acceleration, relative sliding occurs between a first substrate and a plate-shaped proof mass; the relative sliding between the first substrate and the plate-shaped proof mass will reduce the effective area between a first electrode plate and a proof electrode plate, and then the detection capacitor releases the electric charge; an overload detector detects the current, and then judges the acceleration of the MEMS according to the size of the current; when the acceleration reaches a degree at which security measures need to be executed, the sliding distance between the first substrate and the plate-shaped proof mass reaches a degree at which a first substrate round hole and a proof mass hole are overlapped; at this time, micro energy emitted by a micro energy emission unit can pass through the first substrate round hole and the proof mass hole; and a security mechanism triggering unit executes security disconnect measures after receiving the micro energy. The composite function accelerometer is not only small in size, but also has the security judgment function.

Description

Technical Field

[0001] This invention relates to a multifunctional accelerometer, belonging to the field of microelectromechanical systems (MEMS) technology. Background Technology

[0002] In a microelectromechanical system (MEMS), the accelerometer is used to detect overload. The MEMS also contains safety devices to trigger safety measures (alarms, isolation of important components, etc.) when the overload is large.

[0003] Most existing accelerometers and security devices employ machined structures, resulting in large sizes that are difficult to miniaturize. Micro-sized intelligent devices are increasingly used in various fields, such as micro-aircraft, micro-fuzes, and micro-sensor networks; therefore, microelectromechanical systems (MEMS) are accelerating towards miniaturization and lightweight design. The aforementioned application scenarios also place similar functional requirements on accelerometers and security devices, necessitating sufficiently lightweight, integrated, and miniaturized designs.

[0004] Therefore, existing accelerometers and security devices suffer from poor integration and miniaturization. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a composite accelerometer that is lightweight, integrated, miniaturized, and also functions as a security device.

[0006] To achieve the above objectives, this application employs the following technical solution: This application provides a multifunctional accelerometer, including, When the accelerometer with the composite function undergoes acceleration, it can slide against each other due to inertia, which is the first base plate and the plate-shaped inspection quality. The detection capacitor includes a first electrode plate disposed on the surface of the first substrate and an inspection electrode plate disposed on the plate-shaped inspection quality surface. An overload detector is electrically connected to the first electrode plate. The overload detector is used to detect the acceleration of the composite function accelerometer based on the current. The security mechanism triggering channel includes a first substrate circular hole located on the first substrate and an inspection quality hole located on the plate-shaped inspection quality. A micro-energy emission unit and a security mechanism triggering unit are respectively provided at both ends of the security mechanism triggering channel. When the first substrate and the plate-shaped inspection quality slide against each other due to inertia until the first substrate circular hole and the inspection quality hole coincide, the security mechanism triggering unit can be triggered by the micro-energy signal emitted by the micro-energy emission unit.

[0007] In some embodiments of this application, a second substrate located on the side of the plate-shaped inspection quality away from the first substrate, and a second electrode plate disposed on the surface of the second substrate, the second electrode plate being electrically connected to the overload detector; The plate-shaped inspection quality is provided with multiple inspection plates on both sides, which together with the second plate and the first plate form multiple detection capacitors.

[0008] In some embodiments of this application, the security mechanism triggering channel further includes a second substrate circular hole located on the second substrate, the second substrate circular hole being positioned corresponding to the first substrate circular hole. When the first substrate and the plate-shaped inspection mass slide against each other due to inertia until the inspection mass hole coincides with the first substrate circular hole and the second substrate circular hole respectively, the security mechanism triggering unit can be triggered by the micro-energy signal emitted by the micro-energy emission unit.

[0009] In some embodiments of this application, the first substrate and the second substrate are symmetrically distributed on both sides of the plate-shaped inspection quality, and the ends of the first substrate and the second substrate are electrically connected to each other via electrical connection portions, and the overload detector is directly electrically connected to the electrical connection portions.

[0010] In some embodiments of this application, a plurality of first electrode plates are symmetrically distributed on both sides of the first substrate circular hole with the first substrate circular hole as the center; a plurality of second electrode plates are symmetrically distributed on both sides of the second substrate circular hole with the second substrate circular hole as the center.

[0011] In some embodiments of this application, the overload detector is also electrically connected to the micro-energy emission unit, and the overload detector controls the micro-energy emission unit to emit micro-energy signals in response to the detected current reaching a first threshold.

[0012] In some embodiments of this application, the first electrode plate and the second electrode plate are made of monocrystalline silicon material.

[0013] In some embodiments of this application, the plate-shaped inspection quality is made of silicon material.

[0014] In some embodiments of this application, the inspection electrode is connected to the plate-shaped inspection quality via a bonding process.

[0015] Compared with the prior art, the beneficial effects achieved by this application are as follows: The composite accelerometer provided in this application involves relative sliding between a first substrate and a plate-shaped inspection mass when the MEMS generates acceleration. The sliding distance is directly proportional to the acceleration. This relative sliding reduces the effective area between the first electrode plate and the inspection electrode plate, causing the detection capacitor to release charge. An overload detector detects the current and determines the MEMS acceleration based on the current magnitude. When the acceleration generated by the MEMS reaches a level requiring security measures, the sliding distance between the first substrate and the plate-shaped inspection mass reaches the point where the circular hole of the first substrate coincides with the hole of the inspection mass. At this point, the micro-energy emitted by the micro-energy emission unit can pass through the circular hole of the first substrate and the hole of the inspection mass. Upon receiving the micro-energy, the security mechanism trigger unit executes a security disconnection measure. This composite accelerometer, which detects acceleration by detecting changes in the effective area of ​​the detection capacitor, is smaller than existing composite accelerometers that rely on traditional mechanical principles. Furthermore, the composite accelerometer also incorporates a security device, saving space occupied by the security device. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the cross-sectional structure of the composite accelerometer provided in this embodiment when the acceleration is zero; Figure 2 This is a schematic diagram of the cross-sectional structure of the composite accelerometer provided in this embodiment when the acceleration just causes the security mechanism trigger channel to be opened; Figure 3 yes Figure 1 A top view diagram illustrating the quality inspection of medium-sized plates; Figure 4 yes Figure 2 A schematic diagram showing the security mechanism triggering unit receiving micro-energy after the central security mechanism triggering channel is connected; In the figure: 1. First substrate circular hole; 2. First substrate; 3. First electrode plate; 4. Inspection electrode plate; 5. Plate-shaped inspection quality; 6. Second electrode plate; 7. Second substrate; 8. Inspection quality hole; 9. Second substrate circular hole; 10. Overload detector; 11. Micro-energy emission unit; 12. Security mechanism triggering unit. Detailed Implementation

[0018] The technical solutions of this application / the embodiments thereof will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application / the embodiments thereof, and not all embodiments thereof. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this application / the application thereof or its application or use. Example 1

[0019] This embodiment provides a composite accelerometer to address the issues of poor integration and miniaturization in existing composite accelerometers and security devices.

[0020] refer to Figures 1 to 4 The composite accelerometer provided in this embodiment includes, The first substrate 2 and the plate-shaped inspection mass 5; when the composite function accelerometer undergoes acceleration, the plate-shaped inspection mass 5 can slide against the first substrate 2 due to inertia. This mutual sliding constitutes the cornerstone of acceleration (overload) detection and the execution of control and security measures. The composite accelerometer also includes a detection capacitor, which includes a first electrode plate 3 disposed on the surface of the first substrate 2 and a test electrode plate 4 disposed on the surface of the plate-shaped test mass 5. The overload detector 10 is electrically connected to the first electrode plate 3 and is used to detect the acceleration of the composite accelerometer based on the current. The composite accelerometer also includes a security mechanism trigger channel, which includes a first substrate circular hole 1 located on the first substrate 2 and an inspection quality hole 8 located on the plate-shaped inspection mass 5. The two ends of the security mechanism trigger channel are respectively provided with a micro-energy emission unit 11 and a security mechanism trigger unit 12. The inspection quality hole 8 of the plate-shaped inspection mass 5 is offset from each other by default when there is no acceleration. However, when the first substrate 2 and the plate-shaped inspection mass 5 slide against each other due to inertia until the first substrate circular hole 1 and the inspection quality hole 8 coincide, the security mechanism trigger unit 12 can be triggered by the micro-energy signal (such as a light signal) emitted by the micro-energy emission unit 11.

[0021] In use, when the MEMS equipped with the composite accelerometer generates acceleration (overload), relative sliding occurs between the first substrate 2 and the plate-shaped inspection mass 5. The sliding distance is directly proportional to the acceleration. The relative sliding between the first substrate 2 and the plate-shaped inspection mass 5 will reduce the effective area between the first electrode plate 3 and the inspection electrode plate 4, thereby releasing the charge of the detection capacitor. The overload detector 10 determines the acceleration of the MEMS by detecting the current (equivalent to detecting the capacitance value of the detection capacitor). When the acceleration generated by the MEMS reaches the level that requires the execution of safety measures, the sliding distance between the first substrate 2 and the plate-shaped inspection mass 5 will reach the point where the circular hole 1 of the first substrate and the inspection mass hole 8 coincide. At this time, the micro-energy emitted by the micro-energy emission unit 11 can pass through the circular hole 1 of the first substrate and the inspection mass hole 8. After receiving the micro-energy, the safety mechanism trigger unit 12 executes the safety disconnection measure.

[0022] The composite accelerometer that detects acceleration by detecting changes in the effective area of ​​the capacitor is smaller than the existing composite accelerometers that rely on traditional mechanical principles. Furthermore, the composite accelerometer is compatible with the functions of security devices, reducing the volume occupied by security devices.

[0023] It is worth noting that this embodiment does not use the acceleration output by the overload detector 10 as the judgment condition for security intervention. Instead, it directly uses the method that when the sliding distance of the first substrate 2 and the plate-shaped inspection mass 5 reaches a certain level, the circular hole 1 of the first substrate coincides with the inspection mass hole 8, allowing micro-energy to pass through, as the judgment condition for security intervention. This can reduce the errors that may occur in the intermediate process, and the sliding distance of the first substrate 2 and the plate-shaped inspection mass 5 can more accurately and intuitively reflect the magnitude of the actual acceleration.

[0024] In addition, both the plate-shaped inspection mass 5 and the first substrate 2 are planar components, which allows the composite accelerometer to have a planar and compact structure. Example 2

[0025] This embodiment provides a composite accelerometer. This embodiment is an optimization based on Embodiment 1 to improve the technical effect and refine the technical solution. For details not described in this embodiment, please refer to Embodiment 1.

[0026] In one embodiment, a second substrate 7 may be provided on the side of the plate-shaped inspection mass 5 away from the first substrate 2. The detection capacitor also includes a second electrode plate 6 disposed on the surface of the second substrate 7, and the second electrode plate 6 is electrically connected to the overload detector 10. Multiple inspection electrodes 4 are respectively provided on both sides of the plate-shaped inspection mass 5, which respectively form multiple detection capacitors with the second electrode plate 6 and the first electrode plate 3. The second substrate 7 and the second electrode plate 6 have the same functions as the first substrate 2 and the first electrode plate 3. They are technical backups of the first substrate 2 and the first electrode plate 3. When the composite accelerometer is overloaded, the plate-shaped inspection mass 5 slides relative to the first substrate 2. The overload detector 10 can judge the current acceleration of the MEMS by combining the current detected from the first electrode plate 3 and the second electrode plate 6.

[0027] Corresponding to the function of the first substrate circular hole 1, the security mechanism triggering channel also includes a second substrate circular hole 9 located on the second substrate 7. The second substrate circular hole 9 corresponds to the position of the first substrate circular hole 1. (Refer to...) Figure 4 When the first substrate 2 and the plate-shaped inspection mass 5 slide against each other due to inertia until the inspection mass hole 8 coincides with the circular hole 1 of the first substrate and the circular hole 9 of the second substrate respectively, the three holes are connected, and the security mechanism triggering unit 12 can be triggered by the micro-energy signal emitted by the micro-energy emission unit 11.

[0028] As one embodiment, reference Figure 2 The first substrate 2 and the second substrate 7 are symmetrically distributed on both sides of the plate-shaped inspection quality 5. The ends of the first substrate 2 and the second substrate 7 are electrically connected to each other, and the overload detector 10 is directly electrically connected to the electrical connection. As one embodiment, the overload detector 10 is electrically connected to the electrical connection via a wire. When the effective area of ​​the detection capacitor changes, the generated current is detected by the overload detector 10 through the electrical connection between the first substrate 2 and the second substrate 7. At the same time, the electrical connection also serves to balance the charge between the first electrode plate 3 and the second electrode plate 6.

[0029] In one embodiment, a plurality of first electrode plates 3 are symmetrically distributed on both sides of the first substrate circular hole 1, with the first substrate circular hole 1 as the center; a plurality of second electrode plates 6 are symmetrically distributed on both sides of the second substrate circular hole 9, with the second substrate circular hole 9 as the center. Correspondingly, refer to Figure 3 Multiple inspection plates 4 are also provided on both sides of the plate-shaped inspection quality 5, forming multiple detection capacitors with the first plate 3 or the second plate 6 respectively, which improves the detection accuracy. Furthermore, the multiple first plates 3 symmetrically distributed on both sides of the first substrate circular hole 1 with the first substrate circular hole 1 as the center, and the multiple second plates 6 symmetrically distributed on both sides of the second substrate circular hole 9 with the second substrate circular hole 9 as the center, can improve the detection symmetry of the overload detector 10 when the plate-shaped inspection quality 5 slides bidirectionally. Although Figure 1 The plate-shaped inspection quality 5 only has inspection quality holes 8, but those skilled in the art can symmetrically open another inspection quality hole 8 on the other side to realize the bidirectional security function of a single composite accelerometer.

[0030] As one embodiment, reference Figure 4The overload detector 10 is also electrically connected to the micro-energy emission unit 11. When the detected current reaches a first threshold, the overload detector 10 anticipates that the position of the quality inspection hole 8 may coincide with the first substrate circular hole 1 and the second substrate circular hole 9, and controls the micro-energy emission unit 11 to emit a micro-energy signal in advance. By controlling the micro-energy emission unit 11 to emit a micro-energy signal by detecting whether the current reaches the first threshold, the emission energy consumption and invalid emission count of the micro-energy emission unit 11 can be reduced, thereby increasing the emission lifespan of the micro-energy emission unit 11.

[0031] In one embodiment, the first electrode 3 and the second electrode 6 are made of monocrystalline silicon material.

[0032] As one embodiment, the test plate 4 can also be made of monocrystalline silicon. Monocrystalline silicon possesses excellent mechanical, electrical, and thermal properties, meeting the operational requirements of composite accelerometers in various environments. The integrity and uniformity of its crystal structure help ensure the performance consistency and reliability of the composite accelerometer.

[0033] As one embodiment, the plate-shaped inspection mass 5 is made of silicon material and is made of appropriate mass and shape through precise micromachining processes to ensure accurate displacement under overload.

[0034] In one embodiment, the inspection electrode 4 is connected to the plate-shaped inspection quality 5 by a bonding process, including silicon-silicon direct bonding or anodic bonding.

[0035] As one embodiment, reference Figure 1 and Figure 2 The edges of the first substrate 2 and the second substrate 7 can be merged. In addition to serving as an electrical connection, the merged part of the first substrate 2 and the second substrate 7 can also form a partially sealed slide space that constrains the movement direction of the plate-shaped inspection mass 5. When the accelerometer with the composite function accelerates along with the MEMS, the plate-shaped inspection mass 5 can only slide in the slide space by inertia, changing the effective area of ​​the detection capacitor. When the acceleration of the MEMS slows down or stops, the effective area of ​​the detection capacitor gradually recovers as the plates of the detection capacitor attract each other.

[0036] The composite accelerometer provided in this embodiment features miniaturization, low power consumption, and high integration. Its planar structure solves the problems of large size and difficulty in miniaturization of existing composite accelerometers and security isolation devices. It can be used to adapt to micro-miniature intelligent devices with a new type of security and overload sensing structure.

[0037] As one embodiment, the diameter of each opening in this embodiment is on the order of micrometers or millimeters.

[0038] As one embodiment, silicon bulk micromachining processes, such as deep reactive ion etching (DRIE), can be used to fabricate plate-shaped inspection mass 5 with specific shapes and sizes from a silicon wafer. During the fabrication process, it is essential to ensure that the mechanical properties of the plate-shaped inspection mass 5, such as stiffness and mass distribution, meet the design requirements to guarantee that it can accurately respond and generate displacement under acceleration.

[0039] The composite accelerometer provided in this embodiment is suitable for wearable devices, such as smartwatches and smart bracelets, and can be used to monitor the user's motion status and acceleration changes. When the security mechanism trigger channel in the composite accelerometer is activated, it indicates that an abnormal overload situation has been detected. For example, if the user suffers an accidental impact or vigorous exercise resulting in excessive acceleration, the composite accelerometer can promptly trigger the security mechanism. For instance, by cooperating with other modules of the device, it can issue an alarm to the user or take corresponding protective measures, such as locking certain functions of the device to prevent data loss or device damage.

[0040] The multi-functional accelerometer provided in this embodiment is suitable for micro-aircraft, such as micro-drones and small aircraft. It is an important component of flight control systems. It can monitor the acceleration changes of the aircraft in real time during flight. When encountering overload conditions such as airflow impact or collision, the safety mechanism trigger channel is opened, automatically initiating an emergency landing procedure to prevent the aircraft from crashing and causing greater losses.

[0041] The composite accelerometer provided in this embodiment is suitable for miniature fuses. Under normal conditions (storage, transportation, etc.), the three holes do not overlap, and the security mechanism trigger channel is closed to prevent accidental activation of the weapon. In the event of a massive overload (launch process), the security mechanism trigger channel is opened, and the resulting channel can transmit optical trigger signals or micro-energy to accurately activate the fuse and achieve reliable detonation. Its compact size makes it easy to integrate, meeting the requirements for miniaturization and lightweighting of miniature fuses, and it offers stable performance and adaptability to complex environments.

[0042] The multi-functional accelerometer provided in this embodiment is suitable for micro-sensor networks. In a sensor network composed of numerous micro-sensors, each sensor node typically needs to possess certain security and overload monitoring capabilities. The multi-functional accelerometer in this embodiment can be integrated into the sensor node to monitor whether the node is subjected to excessive external impact during installation, transportation, or use. If an excessive overload is detected, the security mechanism trigger channel is activated, and the node can take timely measures, such as pausing data acquisition or sending a fault signal, to ensure the normal operation of the entire sensor network and the accuracy of the data.

[0043] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are used only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0044] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "located in," "equipped with," "located in," "installed," "set," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances. "Hinged connection" includes "rotational connection."

[0045] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An accelerometer with multiple functions, characterized in that, include, When the accelerometer with the composite function undergoes acceleration, the first base plate (2) and the plate-shaped inspection quality (5) can slide against each other by inertia. The detection capacitor includes a first electrode plate (3) disposed on the surface of the first substrate (2) and an inspection electrode plate (4) disposed on the surface of the plate-shaped inspection quality (5). An overload detector (10) is electrically connected to the first electrode plate (3). The overload detector (10) is used to detect the acceleration of the accelerometer of the composite function according to the current. The security mechanism triggering channel includes a first substrate circular hole (1) located on the first substrate (2) and an inspection quality hole (8) located on the plate-shaped inspection quality (5). The two ends of the security mechanism triggering channel are respectively provided with a micro-energy emission unit (11) and a security mechanism triggering unit (12). When the first substrate (2) and the plate-shaped inspection quality (5) slide against each other due to inertia until the first substrate circular hole (1) and the inspection quality hole (8) coincide, the security mechanism triggering unit (12) can be triggered by the micro-energy signal emitted by the micro-energy emission unit (11).

2. The accelerometer with composite function according to claim 1, characterized in that, It also includes a second substrate (7) located on the side of the plate-shaped inspection quality (5) away from the first substrate (2), and a second electrode plate (6) disposed on the surface of the second substrate (7), the second electrode plate (6) being electrically connected to the overload detector (10); The plate-shaped inspection quality (5) is provided with multiple inspection plates (4) on both sides, which together with the second plate (6) and the first plate (3) form multiple detection capacitors.

3. The accelerometer with composite function according to claim 2, characterized in that, The security mechanism triggering channel also includes a second substrate circular hole (9) located on the second substrate (7). The second substrate circular hole (9) corresponds to the first substrate circular hole (1). When the first substrate (2) and the plate-shaped inspection mass (5) slide against each other due to inertia until the inspection mass hole (8) coincides with the first substrate circular hole (1) and the second substrate circular hole (9) respectively, the security mechanism triggering unit (12) can be triggered by the micro-energy signal emitted by the micro-energy emission unit (11).

4. The accelerometer with composite function according to claim 3, characterized in that, The first substrate (1) and the second substrate (7) are symmetrically distributed on both sides of the plate-shaped inspection quality (5). The ends of the first substrate (1) and the second substrate (7) are electrically connected to each other. The overload detector (10) is directly electrically connected to the electrical connection.

5. The accelerometer with composite function according to claim 4, characterized in that, Multiple first electrode plates (3) are symmetrically distributed on both sides of the first substrate circular hole (1) with the first substrate circular hole (1) as the center; multiple second electrode plates (6) are symmetrically distributed on both sides of the second substrate circular hole (9) with the second substrate circular hole (9) as the center.

6. The accelerometer with the composite function according to claim 1 or 4, characterized in that, The overload detector (10) is also electrically connected to the micro-energy emission unit (11). In response to the detected current reaching a first threshold, the overload detector (10) controls the micro-energy emission unit (11) to emit a micro-energy signal.

7. The accelerometer with composite function according to claim 3, characterized in that, The first electrode plate (3) and the second electrode plate (6) are made of single-crystal silicon material.

8. The accelerometer with composite function according to claim 1, characterized in that, The plate-shaped inspection quality (5) is made of silicon material.

9. The accelerometer with composite function according to claim 1, characterized in that, The inspection electrode (4) is connected to the plate-shaped inspection quality (5) by a bonding process.

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